Telephone system



secured in-the block 107 by pins 166 are the two operating arms 109 which extend through the side walls 110 of the main frame and terminate by sliding the plate out sideways and substituting another therefor. This is possible since the plate is retained in the jaws by means of pins 145, which engage depressions in the side of the plate. The pins 145 are held in engagement with the depressions by means of springs 144, the tension of the springs being adjusted by means of the set screws 143. Thus the proper compressor plate may be inserted in the machine depending upon the type of relay spring combination which is to be assembled.

Extending vertically upward from the main frame block 101 is the rod or post 147. This rod is securely fastened in the frame 101.

Mounted on this rod at its upper end is the handle 160 which is pivoted at point 159. The piece 157 fits over the end of rod 147 and is secured. thereto to prevent vertical motion of the piece 157 by means of two pins 158 which extend through the cap 157. These pins engage a groove in the upper end of the rod'147, thereby allowing rota? tion of the cap 157 on the rod.

Loosely mounted on the rod 147 is a block 153, held in position by a shoulder on the rod.147 at its lower end and by the. nut 167 at its upper end.

. The plunger 156 passes through a hole in the other end of the plate or block 153, the plate 153 serving as a guide for the plunger; The plunger has portions cut away on each side near its upper end forming a narrow shank portion 162 which is held loosely between the lever arm 160 and-the clamping plate 161 which is clamped thereto. Portions of the lever arm 160 and the plate 161 are cut Also extending through the block or plate 153 is the hollowed cylinder 168 held in'position by means of the nut 169. The pin 163 extends through this cylinder and the rounded head at its upper end is in contact with the lever arm 160. This pin is held in its raised position by means of the spring 164'which is retained within the cylinder by means of the nut 165 which is threaded on the cylinder 168. From the foregoing it is seen that the lever arm 160 may be swung to one side and that the plate 153, plunger 156, and guide pin 163 move with the'lever arm. An L-shaped plate 150 is secured to the rod 147 by means of bolts 152. A stop screw 151 is threaded through this plate in a position so that the plate 153 strikes against the stop screw when the lever 160 is rotated into the position shown in the drawings. This stop screw'151 may be adiusted so that it will stop the plate 153 with the pins 155 approximately above the holes 146 in the compressor plate .142. In order to exactly align the pins 155 above the holes in the compressor plate, a plate 148 is also secured to the rod 147, and this plate contains a hole 149, counter-sunk at its upper end, so that it will receive the lower end of pin 163. Thus when the lower end of pin 163 passes into the hole 149, the aligning pins 155 will be directly above the holes 146 in the compressor plate.

The compressor is controlled by means of the air valve 117 shown in the lower portion of the drawings. An air line 128 connects this valve to the upper end of the air cylinder 115, and air line 129 connects the air valve to the lower end of this cylinder. The lines 126 and 127 are air-supply and -exhaust lines, respectively. The air valve consists of a rotatable cylinder 118 having a number of pins 119 which are adapted to be engaged by the arm 125 pivoted at point 170 on an extension of the operating lever 120. This lever is pivoted at point 121, as is also the stop pawl or ratchet 124. When there is no assembling fixture in the compressor, the rod 123 is in its raised position due to the spring 136 forcing the pin 132 into recess 111, and the hookend of arm 124 engages one of the pins 119 so that the cylinder 118 cannot be rotated. When an assembling fixture is inserted in the compressor, the fixture operates the pin 132 to the right against the spring tension, thereby forcing therod 123 downward and raising the hooked end of arm 124 out of engagement with the pm 119. The operator may then operate the lever 120 by stepping upon it with his foot, whereby the arm'125 engages one of the pins 119 and rotates the cylinder 118 a quarter of a turn.

-This connects the supply line 129- extending to the lower end of the cylinder to the air-supply line 126 and connects the line 128 extending to the upper end of the cylinder to the exhaust line 127. The piston in cylinder 115 is thereby forced upward, rotating the arm 106 and lowering the block 107. This pulls down the arms 109 and the compressor plate 142. When the lever 120 is again operated, the cylinder 118 is rotated another quarter turn, thereby connecting the air line 128 to the air-supply line 126 and the air line 129 to the exhaust line 127 and forcing the piston to the lower end of the cylinde'r, thereby raising the arms 109 and the compressor plate 142.

The manner of completing the assembly will now be briefly explained. When an assembling fixture, such as shown in Figs. 1 to 3 of the drawings, has the various parts assembled thereon and is passed to the compressor, it is inserted in the recess 111 formed by the side walls 110. The ends of the relay springs fit into the groove 141 in the end of plate 139 which is held to the main frame of the compressor 101 by means ofv screws 140. The fixture operates the pin 132,

thereby unlocking the air valve so that it may be operated. The stop screws 137 allow the assembling fixture to be inserted only the proper distance so that the pile-up of parts is directly below the compressor plate 142. The ends of the contact springs fitting into the groove 141 1 in block 139 serve to further align the various parts of the pile-up. When the fixture has been inserted in this manner, the lever arm 160, which is usually rotated a quarter turn to the left so that it will not interfere with the operator when not in use, is now rotated to the right until the plate 153 is stopped by the stop screw 151.

The lever arm 160 is then pulled'down, the lower end of pin 163 passing into the ho e 149 in the plate 148. This exactly aligns the pins 155 abovethe holes 146 in the compressor plate. As the lever is lowered, the pins 155 pass through the holes 146 in the compressor plate and strike the ends of pins 19 and 20' over which the parts of the article have been assembled. As the lever Jan. 23, 1934. E. EHRICKE TELEPHONE SYSTEM Filed May 25. 1932 2 Sheets-Sheet 2 Erich Ehr'icke Patented Jan. 23, 1934 UNITED STATES PATENT OFFICE assignor to Siemens schaft, Siemensstadt,

& Halske Aktiengesellnear Berlin, Germany Application May 25, 1932, Serial No. 613,355, and

in Germany 4 Claims.

The present invention relates to a circuit arrangement for telephone systems provided with exchanges for the setting up connections of high value, for example, toll connections in systems including small completely automatic sub-exchanges. The toll traffic with the sub-exchanges is then carried out in such a manner that toll connections are set up over an operators position in a neighboring exchange associated with the sub-exchange. On economical grounds it is desirable to reduce the staff at these operators positions during light traflic and to confine the trafiic for a plurality of exchanges during such periods to a common main exchange.

Arrangements are also known in which a subexchange such as, forexample, a factory exchange or the like is switched direct to a main exchange during the periods of light traific, for example, at night time, thus evading the exchange. This arrangement, however, entails the drawback that a comparatively large number of junction lines. between the intermediate exchanges and the main exchange have to be provided for the night traflic due to the fact that each line in the intermediate exchange from a sub-exchange must be connected up to a definite junction line leading to the main exchange.

The problem solved by the present invention is how to utilize the lines to the main exchange more advantageously and consequently reduce the number of junction lines. This is achieved by calls from a sub-exchange normally dealt with by an operator in an exchange being automatically put through during the periods of light traflic (for example at night time) over free hunting, switches to an idle junction line leading to an operators position in another exchange (for example main exchange).

An embodiment of the invention is shown in thev accompanying drawings, said invention being applicable to toll trafiic for systems including small automatic exchanges, so-called rural exchanges.

Fig. 1 shows a theoretical circuit. The small automatic exchanges U1 and U2 are connected to the exchange B during periods of normal traflic such as during the day-time and for setting up outgoing as well as incoming toll connections. The exchange B is provided with the switchboard FPbl for the sub-exchange U1 and the switchboard FPb2 for the sub-exchange U2. The automatic connecting devices in the sub-exchanges U1 and U2 comprise merely the preselectors VW and final selectors LW in the manner indicated for exchange U1. Incoming toll June 19, 1931 connections for the exchange U1 are set up by the operator at the toll position FPbl over the jack K1, repeater Uel, junction line VLl, to the exchange U1. Toll connections to the exchange U2 are set up with the assistance of an operator at the toll position FPb2 over the jack K2, repeater Ue2,and junction line VL2 to the exchange U2. In addition to these connections to be put through manually, the two sub-exchanges U1 and U2 may be automatically accessible for incoming toll calls also from the toll position FPa of a control exchange A over the jack K11 preselector FVW, group selector FGW, junction line VLS and the repeater Uel or U62.

The toll positions FPbl in the exchange B are unoccupied during night time. Toll connections from the exchange U1 in such a casev extend over the junction line VLl, repeater Uel, secondary lineswitch MWl, repeater Ue4, junction line VIA, repeater Ue5 to the jack K12 at the toll position FPa in the central exchange A after the operator at the position FPbl has completed a switching operation to this effect. Similarly, outgoing toll connections from the exchange U2 extend at night over the junction line VL2, repeaterUe2, secondary lineswitch MW2, repeater Ue4, junction line VL4, repeater Ue5 to the jack K12 at the toll position FPa in exchange A. Furthermore, toll connections may also beset up in a third direction, for example, from the exchange U3 to the exchange A, extending over the repeater Ue6, the junction line VLG, repeater Ue'l, secondary lineswitch MW3 which is multiple connected to the secondary lineswitches MWl and MW2, repeater Ue4, junction line VL4, repeater Ue5, to the jack K12 at the toll position FPa in the exchange A.

The individual switching operations will now be described in detail in conjunction with Fig. 2.

When'a toll connection is set up over the. 'toll position FPbl to the sub-exchange U1, relay C1 is energized in the following circuit when the toll operator inserts the appropriate plug; earth, plug St, jack Kl, contact 3711, winding of relay C1, battery, earth. Relay M1 is energized when contact 1301 is closed. This relay cuts off the test circuit for the incoming toll connection from exchange A by opening its contact 10ml. The closing of contact 1601 closes the loop to the preselector VW of the exchange U1 and causes relay R associated with the preselector VW to be energized over: Earth, winding I of relay R, contact 2315, junction line VLl, winding of the repeater Uel, relay S1, contact 19s1, winding of the repeater Uel, contacts 1601, 1411, junction line V'Ll, contact 24, winding 11 of relay R, battery, earth. Relay R is energized and in known manner starts the preselector VW. When the preselector has found a line leading to an idle final selector, relay T is energized over: earth, battery, windings II and I of relay T, c-wiper of the preselector VW, earth applied to the final selector LW. The contacts 2% and 30$ of relay T switch through the two speaking leads. The closing of contact 276 guards the seized line in known manner against further seizures. The final selector LW is now set by means of impulses dialled by the toll operator at the toll position FPbl. Contact new is closed on the return of the dial and a potential is consequently applied to the b-lead. Relay V1 in the repeater Uel is energized. Relay V1 closes its contact 17111 with the object of short-circuiting the windings of the repeater Uel. Earth is applied to the a-lead a number of times corresponding to the actuating of contact nsi during the return of the dial and relay J1 in the repeater Uel, consequently, is intermittently energized, and de-energized. Relay I1, therefore, at contact 1411 opens and closes the line loop switched through to the final selector LW, thus causing the two feeding bridge relay A and B to be intermittently energized and deenergized. These relays cause in known manner the final selector LW to be set to the required subscriber. These switching operations, however, are of no importance for the present invention.

A toll connection from the exchange 'A to the sub-exchange U1 is set up by the operator at the toll position FPa starting the preselector FVW by inserting the plug in the jack K11, (Fig. 1). An idlegroup selector FGW is then seized. Relay B1 is consequently energized over: earth, c-wiper of the group selector FGW (Fig. 2), junction line VL3, contacts 10ml, 12b1, winding I. Due to the closing of its contact 11121, relay B1 is placed in a locking circuit independent of contact 101111 and, at the sametime, puts its high resistance winding II in the locking circuit. Relay 131 by opening contact 8111 cuts off the test circuit for the connecting route to the exchange A utilized for night trafiic. Relay C1 is energized when contact 2111 is closed. Earth applied to the jack K1 over contacts 2121 and 3111 forms a guarding potential and causes a signal to be passed to the operator when plugging in at the toll position FPbl for the purpose of setting up a connection which indicates that the repeater has been seized for another call. The further switching operations for the setting up of the connection to the exchange U1 are performed exactly in the same manner as' that described previously for a toll connection from exchange 13 to the exchange U1.

If a subscriber at the sub-exchange U1, for example, the subscriber Tn, wishes to set up a toll connection he dials the number corresponding to the repeater Uel after having set the preselector allocated to him to an idle final selector which in this case may be represented by the final selector LW. If the repeater is idle the test relay P of the final selector LW is energized in the following circuit: earth, windings I and II of relay P, cwiper of the final selector LW, c-wiper of the preselector VW in zero position, windings I and II of relay T, battery, earth. Relay P in the final selector LW, by closing its contact 31p and 32p switches through the two speaking leads and guards the seized line against further seizures by closing its contact 35p. Relay V is energized by the closing of contact 3310 over: earth, contact 341/, 33p, winding of relay V, battery, earth. Relay V applies the ringing current from the source of supply RQ to the speaking leads and the ringing current is transmitted over the following route: earth, contacts 27y, 32p, b-wiper of the final selector LW, junction line VLl, winding of relay A1, condenser Op, contacts 1501, 14 .1, junction line VLl, a-wiper of the final selector LW, contact 311), winding of relay Y, contact 3612, ringing current source of supply RQ, battery, earth. Relay A1 in the repeater Uel is energized by the ringing current. Relay M1 is energized over winding II due to the closing of contact 18011. This relay breaks the test circuit for the connections from exchange A by closing contact 101111. The following circuit for the signal lamp AL is closed when relay A1 isenergized: earth, contacts 3901, 40521, signal lamp AL, battery, earth. The operator at the toll position FPbl thereupon inserts the plug St into the jack K1 thus causing relay C1 to be energized. Relay C1 cuts 01f the circuit for the signal lamp AL by opening its contact 3901. Due to the closing of contact 1301 a locking circuit for relay M1 is formed over winding I. The opening of contact 1501 cuts off the ringing circuit and the loop is switched through to the ex change U1 by the closing of contact 1601. This causes the two feeding bridge relays Y and Z in the final selector LW to be energized. Relay Y causes relay V to release by opening its contact The circuit for the two feeding bridge relays Y and Z is maintained by means'of contact 4211. The further switching operations are of no importance for the nature of the invention.

The toll position FPbl is unoccupied during the night time. Toll connections from exchange U1 in this case extend to the exchange A. The operator at the toll position FPbl for this purpose depresses the key NT and thereby causes relay N1 to be energized. Relay Nl closes its contact 4121 which prepares the test circuit to the exchange A. An earth potential is re-applied to the jack K1 over contact 22111. If a subscriber of the exchange U1 wishes to set up a toll connection, relay A1 in the repeater Uel is reenergized after the subscribers preselector and final selector have been switched through to the repeater Uel by means of the transmitted ringing current. Relay M1 is energized over contact 18a1 and cuts 011 the test circuit by means of its contact 101111 for toll connections from exchange A. The following test circuit is closed due to the closing of contact 51111: earth, contact 8111, windings I and II of relay Pl, contacts 51111, 411.1, winding I of relay X associated with the secondary lineswitch MWl, contact 4314, winding of relay C4, battery, earth. Relay P1 in the repeater Uel is now energized and connects up relay D1 to the a-lead by means of its contact 21111. It short-circuits the high resistance winding I of relay P1 with the aid of its contact 7111 and thus causes the seized line 'to be guarded against further seizures in known manner. The switch MWl is a free hunting switch or, in other words, a so-called preselecting secondary lineswitch. Consequently, it preselects an idle line. The other secondary lineswitches set to this line, for example, the secondary lineswitches MW2 and MW3 (Fig. 1) are switched through to the succeeding idle line upon the seizure of the secondary lineswitch MWl due to the lack of current in winding II of relay X. Relay C4 in the repeater U64 is energized. Relay C4 closes its contact 4404 and consequently completes the following circuit for relay A5 in the repeater Ue5 of exchange A: earth, battery, contacts 4404, 47d4, junction line VL4, winding of the repeater U05, winding 11 of relay A5, earth. A

circuit for the signal lamp AL5 is closed in the repeater Ue5 as follows: earth, contacts 51a5, 52t5, signal lamp AL5, battery, earth. The operator at the toll position FPa then inserts the plug into the jack K12 and thereby causes relay T5 to be energized. Relay T5 cuts oil the circuit for the signal lamp AL5 by opening its contact 52t5. The following circuit for relay F4 in the repeater Ue 4= is completed when contact 50t5 is closed: earth, contact 50t5, winding I of relay A5, winding of repeater Ue5, junction line VL4, contact 45d4, 49M, winding II of relay F4, winding of relay D4, battery, earth. Relay D4 also is energized in this circuit. Relay D4 switches through the two speaking leads to the repeater Uel by closing its contact 53d4 and 46d4. Relay D1 in the repeater Uel is energized in the following circuit: earth, battery, winding of relay D1, contact 21101, a-wiper of the secondary lineswitch MWl, contact 452%, junction line VL4, winding of repeater Ue5, winding I of relay A5, contact 501:5, earth. Relay C1 is energized over contact ldl. The ringing circuit is cut off by the opening of contact 1501, relay A1 releases and relay M1 is maintained energized over: earth, contact 1301, winding I of relay M1, battery, earth. The closing of contact 1601 switches through the speaking lead to the calling subscriber in the exchange U1 with the result that the operator at the toll position FPa is in a position to receive the calling subsoribers instructions regarding the required connection.

The connection is released by the operator at the toll position FPa withdrawing the plug from the jack K12 which causes relay D5 to release. Relay D1 in the repeater Uel therefore relapses. Relay D1 cuts off the circuit for relay C1 by opening its contact 1111 which in turn causes the remaining relays associated with the repeater Uel to be deenergized.

What is claimed is:

1. In a telephone system, a manual switchboard, lines extending to said switchboard, an-

other line, means effective when said manual switchboard is attended for setting up connections thereat originated on said lines, and automatic switching apparatus effective when said manual switchboard is unattended for automatically extending a connection from any one of said lines to said other line responsive to a call on any one of said lines, said apparatus including a progressively movable step by step switch.

2. In a telephone system, first and second manual switchboards, lines incoming to said first manual switchboard, a line extending to the second manual switchboard, automatic switching apparatus, and means operable at the will of the operator at the first manual switchboard for causing said automatic switching apparatus to operate responsive to a call on any one of said other lines to extend a connection from such other line to said second manual switchboard.

3. In a telephone system, first and second manual switchboards, lines incoming to the first manual switchboard, other lines extending to the second manual switchboard, and means operable at the discretion of the operator at the first manual switchboard and automatically effective responsive to calls on the lines incoming thereto for routing the calls on such lines to the second manual switchboard by way of said other lines.

4. In a telephone system, a group of lines, a manual switchboard through which connections to and from such lines are handled, a second manual switchboard, automatic switching apparatus, and means effective at the discretion of the operator at the first manual switchboard for routing calls incoming to the first manual switchboard over said lines by way of said automatic switching apparatus to the second manual switchboard.

ERICH EHRICKE. 

